For adjusting fluid flow, a wide variety of valve types are known. One type of valve is generally known as a ball valve. A ball valve has a plug or valve body mounted inside a valve housing. A bore or other passageway or passageways is provided through the valve body so that the valve body can be rotated between open, closed and intermediate flow positions. These valves sometimes face certain disadvantages however. For example, the pressure drop characteristic curve when plotted against the rotation of the valve body may have undesirably abrupt or sudden pressure changes. In some instances a more gradual pressure drop is desired. Also, commonly known valves are often subject to undesirable cavitation due to shape pressure transients or high speed flow around edges of the valve opening.
According, it would be desirable to have a fluid control valve that provides desirable characteristics and overcomes the above mentioned difficulties at least to some extent.